Related papers: Universal Bounds for SU(3) Low Energy Constants
Positivity bounds are powerful tools to constrain effective field theories. Utilizing the partial wave expansion in the dispersion relation and the full crossing symmetry of the scattering amplitude, we derive several sets of generically…
These lecture notes concern recent developments in our understanding of the low energy properties of QCD. Significant progress has been made on the lattice and the beautiful experimental results on the Ke4 and K->3pi decays, as well as…
We argue that the difficulties associated with the convergence properties of conventional SU(3) chiral perturbation theory can be ameliorated by use of a cutoff, which suppresses the model-dependent short distance effects in such…
The decay constant of the $\eta$-meson in the framework of 'resummed' chiral perturbation theory is discussed. A theoretical prediction is compared to the available determinations. Compatibility of these determinations with the latest fits…
We study meson resonances with quantum numbers J^P=1^+ in terms of the chiral SU(3) Lagrangian. At leading order a parameter-free prediction is obtained for the scattering of Goldstone bosons off vector mesons with J^P=1^- once we insist on…
We calculate the next-to-leading order corrections to the $SU(2)\otimes SU(2)$ and $SU(3)\otimes SU(3)$ Gell-Mann-Oakes-Renner relations. We use a pseudoscalar correlator calculated from Perturbative QCD up to five loops and use the QCD…
The effects of the CP violating $\theta$ term in the QCD Lagrangian upon low energy hadronic phenomenology are reconsidered. Strong CP violating interactions among Goldstone bosons and octet baryons are incorporated into an effective chiral…
We have constructed the leading order strangeness S=-1,-2 baryon-baryon potential in a chiral effective field theory approach. The chiral potential consists of one-pseudoscalar-meson exchanges and non-derivative four-baryon contact terms.…
A proper estimation of the chiral low-energy constants of Chiral Perturbation Theory is a very important task. To this end resonance chiral Lagrangians have been used fruitfully. We have studied the determination of chiral couplings at…
We obtain explicit expressions for the \eta and \eta' masses and decay constants using U_L(3) x U_R(3) chiral perturbation theory at next-to-leading order in a combined expansion in p^2 and 1/Nc. A numerical fit of the parameters appearing…
We investigate the numerical values of the low-energy constants in the chiral effective Lagrangian for the interactions between the charmed mesons and the lightest pseudoscalar mesons, the Goldstone bosons of the spontaneous breaking of…
In the framework of the SU(3) chiral quark model, the $S-$wave baryon-baryon bound states are investigated. It is found that according to the symmetry character of the system and the contributions from chiral fields, there are three types…
We construct all SU_L(3)*SU_R(3) chirally invariant anomalous magnetic, i.e. involving a Pauli tensor and one-derivative, interactions of one chiral-[(8,1)+(1,8)] meson field with chiral-[(6,3)+(3,6)], [(3,\bar3)+(\bar3,3)], and…
An exposition is made of recent developments using techniques of unitary chiral perturbation theory, $U \chi P T$, which allows one to extend predictions using chiral Lagrangians to higher energies than ordinary chiral perturbation theory,…
Universal low-energy properties are studied for three identical bosons confined in two dimensions. The short-range pair-wise interaction in the low-energy limit is described by means of the boundary condition model. The wave function is…
The baryon masses on CLS ensembles are used to determine the LEC that characterize QCD in the flavor-SU(3) limit with vanishing up, down, and strange quark masses. Here we reevaluate some of the baryon masses on flavor-symmetric ensembles…
In the low energy domain, Chiral Perturbation Theory parametrizes the small chiral symmetry breaking effects, produced by the quark masses $m_u$, $m_d$ and $m_s$, in terms of order parameters of massless QCD. The latter can then, in…
This review addresses the practical convergence of the ChPT series in the p-regime. In the SU(2) framework there is a number of new results, and improved estimates of \bar\ell_3 and \bar\ell_4 are available. In the SU(3) framework few new…
We have performed fits of the pseudoscalar masses and decay constants, from a variety of RBC-UKQCD domain wall fermion ensembles, to $SU(2)$ partially quenched chiral perturbation theory at next-to leading order (NLO) and next-to-next-to…
We consider a class of theories with a $U(1)_X$ gauge symmetry associated with leptonic chiral currents. The low-energy effective field theory includes a light spin-$1$ boson coupled to the electroweak gauge sector via a Wess-Zumino term,…